Isogamous condition with non­-flagellated gamete is found in:

Explanation

(d) : Chlamydomonas hasflagellated gametes which are similar or dissimilar in size. In Volvox and Fucus, non­motile female gametes and motile male gametes are produced (oogamy). Spirogyra has gametes that aresimilar in size (isogamous) and are non­flagellated.